SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e003c70720f009b1cd2e514aafb67b3a3a80176d1e9d772bf3823bb256193c3e' 
  AND token = '4OhMULDNTGHLYfK/nd42O9eCiSUQUdNNX6m8pupRjUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}